The present invention relates to a compressed-gas circuit interrupter with a heater for maintaining the temperature of the high-pressure gas above its liquefaction point.
In a compressed-gas circuit interrupter, particularly of the type employing an extremely efficient arc-extinguishing and dielectric gas, such as sulfur-hexafluoride (SF.sub.6) gas, it is necessary to maintain the temperature of the high-pressure gas above its liquefaction point. The SF.sub.6 gas is suitable for an arc-extinction and insulation of the compressed-gas circuit interrupter. However, the SF.sub.6 gas can easily be liquefied.
For instance, the SF.sub.6 gas of 20.degree. C. under a gauge pressure of 5 atm starts to liquefy at -33.degree. C. the liquefication of the compressed gas results in lowering its density and deteriorating the insulation and arc-extinction performances.
It is conventional to heat the SF.sub.6 gas and prevent it from liquefying. This type of the compressed-gas circuit interrupter is disclosed in, for example, U.S. Pat. No. 3,118,995 to R. G. Colclaser, Jr. et al.